KYOCERA introduces New KC-91 Protective Overcoat for Thermal Printheads Used in Digital Photo Printing

Contributing to improvements in print speed and print quality of dye-sublimation printers

07 February 2012

Kyoto/Neuss – Kyocera Corporation announced the KC-91, a new protective overcoat that can be applied to Kyocera’s thin-film thermal printheads commonly used in dye-sublimation printing applications such as the self-service digital photo printing machines increasingly found in public locations. Kyocera thermal printheads (up to a maximum A4-size) featuring the KC-91 protective overcoat will be sold starting Tuesday, February 7, 2012.


The newly-developed KC-91 protective overcoat demonstrates the following advantages:

  • A reduction in frictional resistance of approximately 50% over Kyocera’s conventional overcoat*1 which is made possible through Kyocera’s proprietary assessment technology as well as improvements in the overcoat materials and film-formation conditions. The result is a reduction in the occurrence of ‘wrinkles’ in the dye-sub ink ribbon, even if the applied energy is increased by 20%, compared to printheads with conventional overcoats.
  • The absolute value of the frictional resistance between the printhead and the ink ribbon is reduced by a maximum of 30%.
  • Resistance to adhesion of residues (burnt deposits of ink or ink ribbon back-coated agents) is increased by approximately six-fold, contributing to improvements in both print speed and print quality.
  • Durability against thermo-chemical wear is increased four-fold, contributing to increased printhead service life.

Development Background

With the increasing proliferation of high-quality digital cameras and camera-equipped smart-phones in recent years, more people are taking and printing digital pictures themselves, and to service the demand to print those digital pictures, an increasing number of self-service photo printing equipment is being installed at department stores and home electronics stores. More dye-sublimation printers are employed in this application than other photo-printing technologies because they offer high print quality and compact size, allowing them to be located almost anywhere.

The dye-sublimation printer, a type of thermal printer, works via a process where the thermal printhead (hereinafter “head”) comes into contact with the ink ribbon and sublimates the ink with the heat of the head to print images on the paper. The color density is adjusted by varying the level of applied heat (applied energy), and increased frictional resistance is created between the head and ribbon as the applied energy increases. Differences in applied energy simultaneously in different locations on the head can result in differences in frictional resistance, causing the ink ribbon to move at different speeds and subsequently wrinkle, which in turn affects print speed and print quality.

Addressing the demand for equipment capable of printing higher quality photos faster, Kyocera has developed the new KC-91 protective overcoat to significantly reduce the likelihood of ribbon wrinkles caused by differential frictional resistances and to improve print speeds and print quality.

With the world’s No.1 market share*2 for thermal printheads, Kyocera strives to develop products that meet diverse customer needs and prove useful in everyday life.

*1 Kyocera's conventional KC-14 protective overcoat and the new KC-91 protective overcoat were compared through continuous printing by commercial printers; based on research by Kyocera.

*2 As of January 31, 2012; based on research by Kyocera.

To learn more details and view performance charts for this product, please see:

Press Material